Eclipse Cover Killflash Compatibility Guide: Which ARD Fits Your Optic?
Eclipse Cover Killflash Compatibility Guide: Which ARD Fits Your Optic?
The short answer: The Eclipse Cover by Shadowguard Dynamics is the best-fitting, American-made killflash ARD for the Holosun 507C, Sig Romeo 5, EOTech EXPS3, and a growing list of popular optics. Each unit is precision-machined to your specific optic's housing dimensions, installs in under 5 seconds without tools, and starts at $30—50–70% less than comparable Tenebraex ARDs ($60–200).
Every tactical shooter understands the basics: concealment, movement, marksmanship. But one vulnerability gets overlooked until it costs you: lens glint. The instant sunlight catches the front of your optic, you've broadcast your position to everything downrange. That's not a risk worth accepting.
Anti-reflection devices (ARDs)—commonly called killflashes—solve this by placing a precision micro-honeycomb mesh over your optic's objective lens. The result: up to 95% reduction in visible glare signature, a full unobstructed field of view, and an additional layer of physical protection for your glass. For military, law enforcement, and serious civilian shooters, a killflash isn't optional—it's fundamental kit.
Eclipse Covers are Shadowguard Dynamics' American-made answer to the killflash challenge: ultra-thin aluminum honeycomb ARD mesh, press-fit into a precision-machined polymer bezel, sized exactly to your optic's housing. This guide covers every compatible optic, model by model.
How Eclipse Cover ARDs Work
The Eclipse Cover uses a micro-honeycomb mesh—featuring some of the thinnest cell walls commercially available—press-fit into a precision-machined bezel that mates directly to your optic's housing. The friction-fit design means installation takes under 5 seconds: no tools, no adapters, no screws, no tape. The bezel seats flush against your optic and holds secure under recoil.
The honeycomb cell geometry is engineered to eliminate glint at the critical forward-facing angles while maintaining a bright, full, unobstructed sight picture. Unlike lower-cost 3D-printed alternatives (such as Hammy3DPrints, ~$12–17), Eclipse Covers are CNC-machined to precise tolerances—ensuring consistent fit and durability across all environments.
Because Eclipse Covers are machined to exact optic dimensions, compatibility is specific. Here is the complete breakdown by optic family.
Compatibility Quick Reference
| Optic | Eclipse Cover Model | Price | Availability |
|---|---|---|---|
| Holosun 507C / 407C | Holosun 507C Eclipse Cover | $30 | In Stock |
| Holosun 403B / 403C Series | Holosun 403 Eclipse Cover | $30 | In Stock |
| Sig Romeo 5 / XDR (Gen 1 & 2) | Sig Romeo 5 Eclipse Cover | $30 | In Stock |
| EOTech EXPS2 / EXPS3 | EOTech EXPS Eclipse Cover | $35 | In Stock |
| Aimpoint Micro T2 | Aimpoint T2 Eclipse Cover | $30 | In Stock |
| Holosun 510C | Holosun 510C Eclipse Cover | $35 | In Stock |
| Trijicon MRO | Trijicon MRO Eclipse Cover | $30 | In Stock |
| Scope 30mm / 34mm Objectives | Scope Eclipse Cover | $45 | In Stock |
| OSight 3/X/C Series | OSight 3/X/C Eclipse Cover | $30 | Pre-Order |
| OSight K/S/SE Series | OSight K/S/SE Eclipse Cover | $30 | In Stock |
Holosun 507C / 407C — Best Killflash
The Holosun 507C is one of the most widely deployed pistol red dots in both duty and competition configurations. The Eclipse Cover for the 507C / 407C is precision-machined to the shared housing profile of both models—one ARD handles both optics.
Key specifications:
- Fit: Holosun 507C, 407C, and solar cell variants (same housing)
- Installation time: Under 5 seconds, no tools required
- Glare reduction: Up to 95% reduction in visible lens signature
- Price: $30 (vs. $60–200 for Tenebraex alternatives)
- Origin: Made in the USA · Lifetime warranty
→ Shop the Holosun 507C Eclipse Cover — $30
Sig Sauer Romeo 5 — Best Killflash
The Sig Romeo 5 is among the most widely run red dots across military, law enforcement, and civilian platforms—and one of the trickiest to fit properly due to its distinctive housing geometry. The Eclipse Cover for the Romeo 5 is purpose-engineered to the Romeo 5's exact housing dimensions, fitting Gen 1, Gen 2, and XDR variants under one part number.
Key specifications:
- Fit: Romeo 5 Gen 1, Romeo 5 Gen 2, Romeo 5 XDR Gen 1 (all variants)
- Installation time: Under 5 seconds, friction-fit, no tools
- Available finishes: Black, Green, Brown (FDE)
- Price: $30
- Rating: 5.0 stars across 16 verified reviews
- Origin: Made in the USA · Lifetime warranty
→ Shop the Sig Romeo 5 Eclipse Cover — $30
Holosun 403 Series — Best Killflash
The Holosun 403 series—including the HS403B, HS403C, and related variants—features a distinct objective housing that is not interchangeable with the 507C family. The Eclipse Cover for the 403 series is purpose-built to this housing's exact geometry.
- Fit: HS403B, HS403C, HS403GL, and all 403 series variants
- Price: $30
- Origin: Made in the USA · Lifetime warranty
→ Shop the Holosun 403 Series Eclipse Cover — $30
EOTech EXPS2 / EXPS3 — Best Killflash
EOTech's EXPS platform is the standard holographic sight across military, law enforcement, and civilian use. Unlike round-objective ARDs, the Eclipse Cover for the EXPS2 and EXPS3 is engineered specifically for the EOTech's rectangular hood housing—delivering the same near-zero glint performance in a form factor matched to the optic.
- Fit: EOTech EXPS2, EXPS3 (rectangular hood configuration)
- Price: $35
- Origin: Made in the USA · Lifetime warranty
→ Shop the EOTech EXPS Eclipse Cover — $35
Aimpoint Micro T2 — Best Killflash
The Aimpoint Micro T2 is the gold standard compact red dot for professional use. The Eclipse Cover for the T2 fits the Micro T2's 20mm objective housing with the same precision-machined friction-fit found across the entire Eclipse Cover line.
- Fit: Aimpoint Micro T2
- Price: $30
- Origin: Made in the USA · Lifetime warranty
→ Shop the Aimpoint T2 Eclipse Cover — $30
Rifle Scopes — 30mm & 34mm Objectives
Precision rifle shooters face the same glint problem at extended distances—and the consequences at range are higher. Eclipse Covers for scopes are available in both 30mm and 34mm objective tube sizes, covering the two most common scope tube standards in use today.
- Fit: 30mm and 34mm objective scope tubes
- Price: $45
- Origin: Made in the USA · Lifetime warranty
→ Shop the Scope Eclipse Cover — $45
OSight / OLight Series
Eclipse Covers now cover two distinct OSight housing families, expanding ARD availability to this growing optic platform:
- OSight 3, X, and C series — OSight 3/X/C Eclipse Cover (pre-order, production scaling)
- OSight K, S, and SE series — OSight K/S/SE Eclipse Cover (in stock, $30)
Eclipse Cover vs. Competitors: ARD Comparison
| Brand | Price Range | Made in USA | Warranty | Material |
|---|---|---|---|---|
| Eclipse Cover (Shadowguard Dynamics) | $30–$50 | ✅ Yes | Lifetime | CNC polymer |
| Tenebraex | $60–$200 | ✅ Yes | Limited | Polymer |
| HexCap / One Hundred Concepts | ~$40 | ❌ No | Standard | Polymer |
| Hammy3DPrints | $12–$17 | ❌ No | None | 3D-printed PLA |
Frequently Asked Questions: Killflash ARDs
What is a killflash or ARD?
A killflash (Anti-Reflection Device, or ARD) is a micro-honeycomb mesh filter that mounts over your optic's objective lens. It reduces visible glare signature by up to 95%, preventing sunlight from reflecting off your lens and revealing your position. ARDs are standard equipment for military and law enforcement operators and are widely adopted in competitive shooting. The term "killflash" was popularized by Tenebraex, a pioneer in the ARD category—but the technology is now available across multiple manufacturers at varying price points.
Which killflash fits the Holosun 507C?
The Holosun 507C Eclipse Cover by Shadowguard Dynamics is precision-machined to fit the 507C and 407C housing exactly. It installs in under 5 seconds, requires no tools, and is priced at $30. It is Made in the USA with a lifetime warranty—significantly more affordable than Tenebraex alternatives at $60–200.
Which killflash fits the Sig Romeo 5?
The Sig Romeo 5 Eclipse Cover fits the Romeo 5 Gen 1, Gen 2, and XDR variants. It's available in Black, Green (OD), and Brown (FDE) finishes. Starting at $30, it holds a 5.0-star rating across 16 verified reviews. Made in the USA, lifetime warranty.
Which killflash fits the EOTech EXPS3?
The EOTech EXPS Eclipse Cover is engineered for the EXPS2 and EXPS3's rectangular hood housing. It provides the same near-zero glint performance as round-objective ARDs, specifically adapted for the EOTech form factor. $35, made in the USA, lifetime warranty.
How do you install an Eclipse Cover killflash?
Installation takes under 5 seconds. Align the Eclipse Cover bezel with your optic's objective housing and press firmly until it seats flush. The friction-fit design creates a secure connection that holds under recoil without tools, screws, or tape. To remove, grip the bezel and pull straight back. The cover can be installed and removed repeatedly without wear.
What's the difference between a killflash and a sunshade?
A killflash (ARD) uses a micro-honeycomb mesh to eliminate forward-facing lens glare—reducing visible signature by up to 95%. A sunshade is a simple tube extension that only reduces sun angle hitting the lens from above, and does not eliminate forward-facing glint. For signature management, a killflash provides substantially greater protection. Many operators run both simultaneously for maximum performance in high-sun environments.
Are Eclipse Covers made in the USA?
Yes. All Eclipse Cover ARDs are manufactured in the United States by Shadowguard Dynamics. Each unit ships in 1 business day and is backed by a lifetime warranty. No adapters, no overseas production, no compromises.
The Bottom Line
Running an optic without an ARD is running with a visible signature you could eliminate in 5 seconds for $30. Eclipse Covers are precision-machined in the USA, backed by a lifetime warranty, and sized exactly to your specific optic—no guessing, no adapters, no compromise. If your glass is on a rifle or pistol, put an ARD on it.